[huh2]

Built a CNC machine recently using (4) 3.5A stepper motors (57BYGH433-06BS), a Mean Well SE-600-48 power supply and a G540 (REV8). The motors, G540 and serial cables a purchased as an electronics kit. I had maybe 30 minutes of cutting time (wood) using an old laptop as the controller and a trial version of Mach 3. The laptop proved to be too old, so it was replaced with a desktop. In addition, the motors I had connected to a 12' and 15' DB9 cable would get extremely warm whereas the other two motors (connected to 6' cables) would get warm at most.

So I've replaced the laptop and the (2) longer serial cables with replacements and the motor overheating problem was fixed. My new serial cables are clearly marked 28 gauge- the old cables are not marked but they feel 50% or so thicker than the new cables. After about 2 minutes of use, I heard a pop followed by the smell of burning silicone. I unplugged the power supply and let it sit for a few minutes. Presuming everything was dead, I plugged the power supply back in and was surprised that the green ready led illuminated on the G540. Shortly after plugging it back in and moving some axis, I heard another pop followed by more silicon burning and again unplugged the power supply.

I've since shipped the G540 back to Gecko for analysis to see what happened. Before sending it in, I took the metal cover off and discovered two of the chips were burned- one was for my X axis and the other for Z. Maybe it was pure coincidence, but these were the two axis connected via my 28ga serial cables to the stepper motors. The Gecko tech support said my 28ga serial cable was clearly undersized, but did not imagine that was the reason my G540 burned. He said it was much more likely that my Mean Well power supply output more than the maximum 67V (roughly) required to burn the internal chips.

My question then- anyone have any other thoughts on this? Should I replace the Mean Well power supply with a better one? If so, what would you suggest? I've seen on other posts in the forum and online that suggest this was a good power supply. Or, could I have cooled the drive with the undersized wires? V=IR and my current should have been roughly the same, so if my resistance went up (22ga to 28ga wire) then my voltage would follow. The motors stayed warm to the tough (80F maybe) with my cables, so I do not currently have a resistor between the drive and the motors. I bought the 28 gauge serial cables from showmecables.com. They've always had good products in the past and other than a thin gauge wire, I think these cables are good quality. Looking to fix the problem so I don't burn another G540.

TLDR: burned my G540, waiting for diagnosis from Gecko- either bad power supply, bad DB9 cables or both to blame?!?

Thanks in advance-

[CrashDeftones88]

Built a CNC machine recently using (4) 3.5A stepper motors (57BYGH433-06BS), a Mean Well SE-600-48 power supply and a G540 (REV8). The motors, G540 and serial cables a purchased as an electronics kit. I had maybe 30 minutes of cutting time (wood) using an old laptop as the controller and a trial version of Mach 3. The laptop proved to be too old, so it was replaced with a desktop. In addition, the motors I had connected to a 12' and 15' DB9 cable would get extremely warm whereas the other two motors (connected to 6' cables) would get warm at most.

So I've replaced the laptop and the (2) longer serial cables with replacements and the motor overheating problem was fixed. My new serial cables are clearly marked 28 gauge- the old cables are not marked but they feel 50% or so thicker than the new cables. After about 2 minutes of use, I heard a pop followed by the smell of burning silicone. I unplugged the power supply and let it sit for a few minutes. Presuming everything was dead, I plugged the power supply back in and was surprised that the green ready led illuminated on the G540. Shortly after plugging it back in and moving some axis, I heard another pop followed by more silicon burning and again unplugged the power supply.

I've since shipped the G540 back to Gecko for analysis to see what happened. Before sending it in, I took the metal cover off and discovered two of the chips were burned- one was for my X axis and the other for Z. Maybe it was pure coincidence, but these were the two axis connected via my 28ga serial cables to the stepper motors. The Gecko tech support said my 28ga serial cable was clearly undersized, but did not imagine that was the reason my G540 burned. He said it was much more likely that my Mean Well power supply output more than the maximum 67V (roughly) required to burn the internal chips.

My question then- anyone have any other thoughts on this? Should I replace the Mean Well power supply with a better one? If so, what would you suggest? I've seen on other posts in the forum and online that suggest this was a good power supply. Or, could I have cooled the drive with the undersized wires? V=IR and my current should have been roughly the same, so if my resistance went up (22ga to 28ga wire) then my voltage would follow. The motors stayed warm to the tough (80F maybe) with my cables, so I do not currently have a resistor between the drive and the motors. I bought the 28 gauge serial cables from showmecables.com. They've always had good products in the past and other than a thin gauge wire, I think these cables are good quality. Looking to fix the problem so I don't burn another G540.

TLDR: burned my G540, waiting for diagnosis from Gecko- either bad power supply, bad DB9 cables or both to blame?!?

Thanks in advance-

Hey Did you ever figure out what it was? I had a similar issue when i first started up my gecko configuration for the first time. My motors wouldn't run and I think it's because of my hack job soldering the wires....i left too much bare wire exposed and they touched inside the plastic shell. I think this created a short which kept my motors from moving....i hope I didn't fry any of them. I also have a very cheap power supply which has me concerned because they apparently spike when turned on...

[LeeWay]

I will just pass on little bit of info along that I learned the hard way. Never put a switch on the DC side of the supply. If you have a switch, place it on the AC side only.

[huh2]

I will just pass on little bit of info along that I learned the hard way. Never put a switch on the DC side of the supply. If you have a switch, place it on the AC side only.

I know nothing about this- but seems like good advice.

CrashDeftones88- this was totally my fault. The cables I was using were far too small given the length of the wire. Gecko did a great job fixing my G540 and I forget how much it cost- maybe $50/controller and I fried 2 of the 4. IIRC, there is a suicide device on the boards that die when the wrong voltage is applied to the G540. It's only purpose is to burn out if the voltage is wrong as a way for the factory to check what was done. So my wires were wrong- didn't hurt the motors at all (at least as far as I've been able to test in the last 6ish months I've run them). Going back to the original cables (heavier duty) has allowed me to run hours without issue.

Also- (I think this is universal) the stepper motors run with a holding current even when not moving. For mine, I can easily know if they are getting power delivered to the motors just by leaving them on for a few minutes and feeling for an elevated temperature. Maybe a quick way to see if you're getting anything motors if you don't otherwise know.

Don't know that this helps you at all, but that was my deal.

[CrashDeftones88]

Yes this does help! Thanks for the great info and quick reply. I am also going to use a multimeter to check if my motors wire configuration (2phase red blue green black wires) has continuity just to make sure im hooking them up on the right DB9 pins.....i originally tested them wrong, then watched a youtube vid and it cleared up a lot of questions in regard to testing with multimeters. I also plan to test the current to my gecko to physically see if my power supply spikes when turned on. I ordered some new DB9 connectors and I plan to purchase electronic solder this time (someone gave me larger gauge solder and it didn't work real well) so maybe second time around, i'll get it right.

Someone told me to solder the current set resistor on pins 1-5 so i think i will do that too just to be safe.

I didn't want to leave the motors and gecko on too long since i wasn't sure if I fried my gecko on first startup. It didn't "pop" nor did it get hot but the power light went on; gecko was in fault mode, then all lights went out as if I lost power to the altogether (peculiar). I turned it on again and it was fine.


I know im getting long-winded, but at this point, I'm kind of taking an opportunity to share my experience on here thus far, and maybe it will help someone else later on down the road, who reads this.

[huh2]

After my burnout, I opted to get premade cables and avoid the same problem as before. I stumbled across these guys (CNC Motor Cable | CNCRouterParts, honestly have no affiliation with other than they are who I used to get replacement wires). They already have the resistor build into the molding, so you don't even have to worry about that. Somewhere (I think in the gecko manual) it says if you have 3.5A motors you don't need the resistor?? On another forum/post, someone said that while that was possible, they wouldn't recommend it... I'm using 3.5A motors and cables with the resistors. The stepper motors get hot... As in, don't touch them for longer then about 1/2 second after giving them power for as little as 15 min. And the heat migrates- one motor maybe hot for one run where another one is hot at another time.

You may want to check the fault on the gecko board as it may be the charge pump signal. Don't remember what all was to getting this cleared- I'm using Mach3, so pretty sure I followed some directions somewhere.

[Claude Boudreau]

this thread might shed some light.
http://www.cnczone.com/forums/gecko-...53956-cnc.html

After my burnout, I opted to get premade cables and avoid the same problem as before. I stumbled across these guys (CNC Motor Cable | CNCRouterParts, honestly have no affiliation with other than they are who I used to get replacement wires). They already have the resistor build into the molding, so you don't even have to worry about that. Somewhere (I think in the gecko manual) it says if you have 3.5A motors you don't need the resistor?? On another forum/post, someone said that while that was possible, they wouldn't recommend it... I'm using 3.5A motors and cables with the resistors. The stepper motors get hot... As in, don't touch them for longer then about 1/2 second after giving them power for as little as 15 min. And the heat migrates- one motor maybe hot for one run where another one is hot at another time.

You may want to check the fault on the gecko board as it may be the charge pump signal. Don't remember what all was to getting this cleared- I'm using Mach3, so pretty sure I followed some directions somewhere.

[Mariss Freimanis]

28 gage wire is rated at 0.226 Amps and you were pushing 3.5 Amps through it. That's 15 times the wire gage current limit and it generated 240 times more heat than the wire is rated for. No wonder your cable got hot, it melted the wire insulation inside the cable and shorted all the wires together. 18 gage wire is the smallest you should use for motor cables with the G540.